Telephone system and apparatus.



C. L. GOODRUM.

TELEPHONE SYSTEM AND APPARATUS. APPLICATION FILED FEB-3.1910.

1,226,966. Patented May 22, 1917.

2 SHEETS-SHEET I.

$ZQLM @E A445, QM a L A C. L. GOODRUM.

TELEPHONE SYSTEM AND APPARATUS.

APPLICATION FILED FEB. 3, I910- Patented May 22,1911

2 SHEETS-SHEET 2- CHARLES L. GOODRUM, OF URBANA, OHIO ASSIGNOR, BY MESNEASSIGNMENTS, T0

WESTERN ELECTRIC COMPANY, INCORPORATED, A CORPORATTON 0F NEYV YORK.

TELEPHONE SYSTEM AND APPARATUS.

Siecification of Letters Patent.

Patented May 22, 191

Original application filed April 1, 1905, Serial No. 253,227. Dividedand this application filed February 3,

1910. Serial No. 541,811.

To all whom it may concern:

Be it known that 1, Cinemas LANE (loon- RUM, citizen of the UnitedStates, residing at Urbana, in the county of Champaign and State ofOhio, have invented certain new and useful Improvements in TelephoneSystems and Apparatus, of which the following is a specification.

My present invention relates to and has for its object toprovideimproved electromagnetica'lly operated switches adap ted particularlyfor use in connection with automatic telephone systems, such as the oneillustrated in my prior application, Serial No. 253,227, filed April 1,1905, entitled Telephone systems and apparatus of which this applicationis a division.

While switches embodying my invention may be used for purposes otherthan the one mentioned, they relate more particula ly to the art oftelephony and are adapted to be employed in making connection betweentwo or more telephone lines or the trunk circuits of an automatictelephone exchange arranged between and interconnecting'a plurality ofsuch switches. The automatic switch of this invention comprises a momble contact member and groups of contact terminals arranged in a rowwith which said contact member cooperates, electromagnetic means beingprovided for moving said contact member past said terminals to select agroup thereof, and for controlling the return of said contact member toefiect the selection of a contact terminal in the selected group.

In the drawings:

Figure 1 is a plan view of a switch con structed in accordance with myinvention.

Fig. 2 is a longitudinal View thereof taken on the line 2 2 of Fig. 1.

Fig. 3 is a detail sectional view taken on the line 3 -3" of Fig. 2.

Fig. 4: is a detail of some of the contacts and the manner of supportingthe same.

Similar reference characters in the several figures indicate similarparts.

In the present case, instead of employing the double motion switchescommonly known as the Strowger switches" the same having been improvedby Messrs. Lundquist, Ericson and others, I have adopted a verydifi'erent design. In the first place,

my switches are all mounted upon l'lat bases, so they can be mountedlike drawers in a cabinet; and in the second place i make themseparable, one part carrying the contact banks and multiple wiringconncc ns, and the other part carrying the relays and the workingmagnets together with the switch arms or wipers. These second parts areprovided with contact terminals which when the parts are in positionregister with corresponding terminals on the first parts, completing theconnections of the relays. etc. These second parts are removable and allof the same kind are interclmngeablc, and as it is with these parts thata very large percentage of the troublesoccur, it is obvious that I haveachieved an im ortant end by this arrangement; for in case of anytrouble with the working parts of a switch, it is only necessary toslide out the defective switch body and slide in another in its place.

I have chosen to depart from the decimal system of trunking becausethereby T can simplify the switches and get better results. In theordinary Strowger switch it is customary to step up the switch arm tothe row of contacts desired, and then operate a socalled rotary magnetwhich would carry the wiper around continuously until it rests upon anidle contact. In the present case I provide fifty contacts in the switchdivided into groups of five. The groups of five small contacts are equalin angular dimension and each is overlaid by a single broad contact.Each switch has a double ratchet motion; a pawl working into a coarseratchet first steps the wipers around to the group contact desired,clearing five of the small contacts at a jump; then an escapement pawlworking into a finer ratchet (live to one of the other) steps back thewipers one step at a time in the group thus selected until the desiredunit contact is reached. Thus in these switches 1 only give five trunksto a switch, and T can multiply the number of switches if desired.

In illustrating my invention I have shown the switch mechanism mountedupon a base comprising the parts E and c, divided on the line 0 theformer comprising a base upon which operating mechanism is mounted,which is removable from the part c, the

latter being provided with the bank of contacts 1F and being adapted tobe ri idly attached or supported on a circuit frame or within a cabinetso that the removaole part of the base E may be applied thereto.

Upon the base 6 is a row of socket con tacts H mounted in insulation,with which cooperate the contact terminals 7L mounted in a strip on thebase it. These terminals 71, are used to complete the circuit to the magnets shown on the base E hereinafter referred to.

The contact banks F are termed as an arc of a circle somewhat less than180 and concentric. with the center or axis 7) ot the switch spindle. inthe blllllin are the broad contacts 4L8 and individual trunk contacts m.

The switch mechanism comprises a progres ively movable element 6 whichadapted to be advanced step by step and to this end is made circular inform and is mounted on the revcluble shaft 7), the lower end of theshaft l ing journal/ed in the base plate ll, the othe; end beingjournaled in abracket 0', the ends of which are extended downwardly andare detachably secured to the base plate by fastening devices. such asscrews. Carried on the movable elementand insulated therefrom and fromeach other are contact springs or wipers indicated by 6 7F 6 7), 5 Anydesired number of these ipers may be employed and they are arranged asshown one below the other and have at their rear ends segments, asindicated by 7), with which cooperate spring brushes 6 supported in aninsulated holder a secured to one of the legs of the bridge. Each brushhas a tail 6 for the attachment of its circuit wire and an extension 7)which receives the wiper when turned all the way around to clear it fromthe bank contacts and hold it in proper position for reengagcmenttherewith, this clearing being necessary when the plate E and itsattached parts are removed from the bank. To facilitate the removal andreplacing of the plate in proper alinement with the plate 0 of thebanks, I provide a pair of guide tongues attached to the plate (2 andoverlying the plate E when in position. The bank as a. whole is carriedon tour posts best shown in Fi 's. 3 and l, and each bank of contacts isbuilt up of insulating segments with the contacts radially interposedbetween them, the whole being held together by upper and lower segmentalp ates f secured by through-bolts or screws 7. Connected to the lowerend of the shaft 6 is a coil-spring 7) arranged in a. casing to whichits outer-end is attached the tension a ppliedto the spring beingsuflicient to return the shaft and the parts sup ported thereon to theirnormal position, shown in Fig. 1', when they are released.

Cooperating with the ratchet teeth b on the wheel 6 is a pawl 7) on adog 7), pivoted in a yoke attached to the base plate E, as shown inFigs. 1, 2 and 3. The dog has a. joint in the middle and a springnormally tending to throw it up with the pawl engaging teeth 7).looperating with this pawl to form an escap -nent is an armature lever7) of the magnet M this lever having a chisel edge to enter the teethand a bar b to withdraw the pawl as the edge enters by forcing up thetail 7) of the dog.

Opposite the ratchet the dog has a toe 7), with which cooperates a hookon the end of a spring 7) carried on the end of the armature lever ofthe release magnet M. \Vhen this armature is attracted, the pawl 72being up, the spring reaches up, the hook takes hold of the toe andpulls down the dog, permitting the spring 7) to return the spindle 7)and all of its wipers to zero position.

In order to step the wheel 7)* around, the armature lever 7) of themagnet M carries a pawl 7) pivoted at b on said lever and having aangle-stop 7) which comes against a fixed stop 7) on the bridge 0, whenthe magnet is deenergized as shown in Fig. 1. A spring 79 secured at oneend to a projection on the armature 7) and at the other end to somestationary part, normally tends to hold the armature 7) in retractedposition as shown in Fig. 1. As the magnet M is energized its verticallever 7) is thrown to the left against the tension of the spring 7) anda projection on the lower part thereof comes against the spring 7) toremove it from the toe 7) and thus permits the retaining pawl 7) to riseinto engagement with the teeth 7). The tension of the spring 7P tends tokeep the angle stop against the fixed stop 7) so that as the armaturelever 7) moves, its movement will cause the pawl. 7) to swing about itspivotal point 7) until the pawl. engages with the teeth 7) and admncesthe wheel 7)" a space of one notch. Each tooth on this wheel 7) will.move the cont-act arms around ver five contacts M at a jump, equal tothe distance of one broad contact -18, while each tooth 6 moves thecontact arms over one contact singly. As the pawl 7) pushes the wheel 7)around, the toe 7) on the upper end of the armature lever comes over inthe path of and serves as a stop for the teeth on the second wheel 7/furnishing a positive stop for each step in the rotation.

The operation of the switch is then that the action of the magnet M willadvance the wipers, depending upon the number of impulses through saidmagnet, the pawl 7f holding the movable element in its advancedposition. The action of the magnet M permits the movable element 7) tomove backwardly step by step over the individual contacts 3 through themedium of its operating spring I), the number of steps back wardlydepending upon the number of im pulses through said magnet M The actionof the release magnet restores all the parts to their normal position bypulling down the pawl m in the manner described, and permitting themovable element 6* to move back by the action of its spring 6 until thestop 5 thereon comes against the legs of the bridge as shown in Figs. 1and 3.

Having thus described my invention, I claim:

1. In an automatic telephone exchange switch, contacts arranged ingroups, each group constituting trunk terminals, a switch contact andmeans to bring said switch contact into active relation with the lastcontact of a definite group of said contacts, and means to cause saidswitch contact to step backwardly until it becomes operativelyassociated with one or another of said contacts in said group.

2. In an automatic switch, for telephone exchanges, a series of contactsin circular re lation, a concentrically mounted arm sweeping over saidcontacts, and means to cause said arm to make long steps in onedirection and relatively shorter steps or movements in the oppositedirection.

3. In an automatic switch for telephone exchanges, a spindle, two wheelson said spindle, and two pawls cooperating with said wheels, one to setthe wheels forward by long steps, and the other to move the wheelsrearwardly by short steps.

4. A switch for automatic telephone exchanges comprising a base having astationary portion and a relatively movable part thereon, a bank ofcircularly-arranged terminal contacts mounted on the stationary part,and a concentrically mounted element on the movable part of the base andcooperating with the contacts, means for operating said element in longsteps and separate means for operating said elements in relativelyshorter steps, electromagnetic de vices for controlling the respectivestepping means, said stepping means being supported on the movable partof said base.

5. In a switching mechanism, a plurality of terminal contacts arrangedin an are shaped row and an underlying base or support provided withparallel ways, a base plate detachably connected to the support andfitted in said ways, a revoluble element journaled on the plate tocoeperate with said contacts and mechanism for operating said elementcomprising two sets of stepping devices, one for long and one for shortsteps which mechanism is also carried on the movable plate.

6. In a progressively movable switch for automatic telephone systems,the combination with a row of terminal contacts and a movable contactelement cooperating therewith, a movable part havmg ratchet teetharranged in two series in opposite di arm havmg an engaging rections, avibratin portion to contact with one set of teeth and a pivoted pawl toengage the other series of teeth, and means for vibrating said arm asand for the purpose specified.

7. In a progressively movable switch for automatic telephone systems,the combination with a row of terminal contacts and a movable contactelement cooperating therewith, ratchet wheels having relatively shortand long teeth, a series of auxiliary ratchet teeth arranged in oppositedirections from the teeth in the wheel, and a vibrating part having apawl for turning said ratchet wheel and an engaging part for engagingthe auxiliary teeth to prevent overthrow, as and for the purposespecified.

8. In a progressively movable switch for automatic telephone systems,the combination with a row of terminal contacts and a movable contactelement cooperating there with, ratchet wheels with relatively long andshort teeth and pawls for engaging the same, of a series of auxiliaryteeth or stops and an engaging part operating with a pawl and adapted toengage said stops and limit the throw of said pawl when the switch isbeing moved in long steps.

9. In a progressively movable switch for automatic telephone systems,the combination with a row of terminal contacts and a movable contactelement cooperating therewith, a movable element, and a ratchet wheelmoving with said element, a spring for moving said element to its normalposition, a holding pawl operating against the tension of said spring,and an escapement pawl adapted to operate in connection with saidholding pawl to permit the wheel to turn backwardly step-by-step by thecooperation of said escapement and holding pawls, as set forth.

10. In an automatic switch for telephone exchanges, groups of terminalsarranged in a row, a contact arm therefor, and means to cause said armto move over said terminal groups to the end of the desired group, andthen to step backwardly to select a contact in said group.

11. In an automatic switch for telephone exchanges, sets of trunkterminals arranged in groups, a contact arm therefor, andelectromagnetic means to cause said arm to move over said groups to thelast set of terminals therein, and then to move backwardly to select acontact set in said group.

12. In an automatic switch for telephone exchanges, the combination witha selector apparatus having a movable contact member and groups ofcontact terminals arranged in a row with which said member cooperates,

means for moving said contact member past said contact terminals toselect a group thereof, and means for controlling the return of saidmember to effect the selection of a contact terminal in the selected rou3.

18. In an automatic switch for telephone exchan e systems, thecombination with a selector switch comprising a spring-retracted movablebrush and a row of line terminals arranged in groups, electromagneticmeans for moving said contact member past said terminals to select agroup thereof, and an escapement mechanism including a magnet to releasesaid brush step by step to effect the CHARLES L. GOODRUM.

lVitnesses CHAS. I. lVELoir,

0L1 VER T. CLARKE.

Gopies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents. Washington, D. G.

